using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using MyWebApi.Api.Repository;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using System.Text;
using MyWebApi.Api.ParamModel;
using MyWebApi.Api.Filters;

namespace MyWebApi.Api
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }
        // 跨域
        private string allowCors = "AllowCors";


        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // 跨域
            services.AddCors(Options =>
            {
                Options.AddPolicy(allowCors, builder =>
                {
                    builder.AllowAnyHeader()
                    .AllowAnyMethod()
                    .AllowAnyOrigin();
                });
            });


            // 注册数据库上下文到容器中
            services.AddDbContext<MyWebApi.Api.Db.MyWebApiDb>(o => o.UseSqlServer());
            // 注册对数据库的基本操作到容器
            services.AddScoped(typeof(IRepository<>), typeof(EfRepository<>));

            // 注册Token的验证器（使用何种配置来验证Token）
            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(option =>
            {

                // Token的配置

                // 是否要求使用Https
                option.RequireHttpsMetadata = false;
                // 是否保存Token
                option.SaveToken = true;
                // 使用配置的中间件，获得Token的配置(GetSection("tokenParameter"):tokenParameter获取的是appsettings.json文件中的tokenParameter节点)
                var tokenParameter = Configuration.GetSection("tokenParameter").Get<TokenParameter>(); // Get<TokenParameter>(): 中的TokenParameter用的是ParamModel中的TokenParameter实体

                // Token验证器的核心属性
                option.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = true,// 要不要生成Token的密钥
                    IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(tokenParameter.Secret)),
                    ValidateIssuer = true,//   要不要验证发行Token的人（个人或组织）
                    ValidIssuer = tokenParameter.Issuer,
                    ValidateAudience = false    // 是否验证受众
                };
            });

            // 注册审计日志
            services.AddControllers(options =>
            {
                options.Filters.Add(typeof(AuditLogActionFilter));
            });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseStaticFiles();   // 静态文件处理

            app.UseRouting();

            // 将Token的验证注册到中间件
            app.UseAuthentication();

            app.UseAuthorization();

            // 跨域
            app.UseCors(allowCors);

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}
